A Novel Yttrium(III) Complex for Estimating Dopamine in Pure and Pharmaceutical Dosage Forms

A simple, rapid, sensitive, accurate, precise, and cost-effective spectrophotometric method has been developed to estimate dopamine in pure and pharmaceutical dosage forms based on the redox reaction of dopamine in an acid medium with Yttrium(III)  ion as an oxidizing agent. The latter suffers reduction to Yttrium(II)  ion and reacted with 1,10-phenanthroline to form a colored product peaking at 510 nm. Beer's law is obeyed in the concentration range of 0.5-10 μg mL−1 with a molar absorptivity of 1.16x104 L mole−1 cm−1, Sandall's sensitivity of 0.0131 μg.cm-2 ,the recovery rate of dopamine in pharmaceutical dosage was in the range of 98.97 to 101.57%. The effects of variables such as oxidizing agent, reagent concentration, time of oxidation reaction, surfactant, formation constant of the complex, have been investigated to optimize the procedure. The results have been validated analytically and statistically. The proposed method has been successfully applied to estimate dopamine in pharmaceutical dosage forms.